Congenital Heart Disease Etiology
Congenital Heart Disease Etiology
Congenital Heart Disease Etiology
Etiology
Environmental
genetic
multifactorial causes
Chromosomal abnormalities
40% of those with Down syndrome can have a cardiac defect, with atrioventricular septal
defect and ventricular septal defect accounting for approximately 80% of lesions.
Turner’s syndrome, 45XO, left heart lesions with Coarctation of the aorta in 10% of
cases.
CATCH 22 syndrome: cardiac defects, abnormal facies, thymic aplasia, cleft palate,
hypocalcemia.
DiGeorge syndrome
Teratogens
maternal infection
illness
ingestion of certain drugs
Syndromes
de Lange= VSD
Williams = supravalvar aortic stenosis,
Friedreich’s ataxia =hypertrophic cardiomyopathy
Jervell and Lange-Nielsen =prolonged QT
Holt–Oram = atrial septal defect,
VATERL=VSD
Recurrence Risk
risk for another pregnancy rises to about 2% if one previous child is affected
Determine of how each of the three basic components or segments of the heart are
connected.
Atrial arrangement
The right main bronchus is more vertical and shorter than the left,
branching above the lower lobe pulmonary artery while the left branches below it.
The right atrium lies on the same side as the right bronchus.
Careful analysis may show bilateral manifestations of right or left atrial morphology,
which can then be described as right or left atrial isomerism.
Atrioventricular connection
The atrioventricular connection then describes the way the atria communicate
with the ventricles at the atrio-ventricular junction.
If the connections follow the normal pattern they are said to be concordant, e.g.
right atrium to right ventricle and left atrium to left ventricle,
When both atrio-ventricular valves enter one ventricular chamber, the connection
is described as double inlet
if one or other atria is not directly connected to a ventricle, then that atrio-
ventricular connection is said to be absent.
ambiguous: with atrial isomerism and one atrium entering each ventricle
absent right or left: no true or potential connection from the right or left atrium to
a ventricle.
Ventriculoarterial connection
This describes the means by which the great arteries take origin from the
ventricular chambers.
If an artery overrides the septum, and thus arises from both ventricles, it is
assigned to that from which more than half takes origin.
Relationships
Additional abnormalities
Cardiac position
When the heart is on the left side this is not usually stated if there is situs solitus,
Dextrocardia describes the situation in which more than half of the cardiac
shadow on X-ray is in the right side of the chest
it makes no assumptions as to the atrial situs or intracardiac anatomy.
Mesocardia is used when the heart appears to be in the center of the thorax.
Comment
not required in the majority of patients who have normal chamber connections,
morphology and relations.
use the terms which have been in use for some time
The patient with congenital heart disease who survives beyond infancy has a good
outlook,
Nowadays surgery generally carry a low risk.
Infant with congenital heart disease may show rapid progression to severe cardiac failure
or cyanosis with hypoxia and acidosis
Heart disease in the newborn is usually recognized by the presence of cyanosis or heart
failure.
in response to hyperoxia (80–100% oxygen) - a PO2 of over 150 mmHg (21 kPa) from
the upper body excludes a major right to left shunt and a failure to rise suggests a cardiac
defect.
With coarctation of the aorta or hypoplastic left heart syndrome the femoral pulses may
feel normal initially when the ductus is open.
Low volume pulses occur with obstruction to left ventricular output such as hypoplastic
left heart syndrome or severe aortic stenosis.
A parasternal or subxiphoid heave may indicate the presence of a significant defect in a
patient where there is no abnormality on auscultation.
A single second heart sound should be considered abnormal after the first day of life.
When a murmur is heard it is not diagnostic but suggests the presence of an underlying
defect.
ECG
contour of the heart and the great arteries and the effect of the anatomical
abnormality on the pulmonary vascularity
increased pulmonary blood flow is not always reflected in the X-ray appearances.
Prostaglandin therapy
The use of E-type prostaglandins to dilate the ductus arteriosus is an essential part in the
management of the newborn infant with a ductus dependent circulation. T
Prostaglandin E2, which is readily available in most obstetric hospitals, is cheaper than
prostaglandin E1, and equally effective